In a typical cellular radio system, wireless terminals (also referred to as user equipment unit nodes, UEs, and/or mobile stations) communicate via a radio access network (RAN) with one or more core networks. The RAN covers a geographical area which is divided into cell areas, with each cell area being served by a radio base station (also referred to as a RAN node, a “NodeB”, and/or enhanced NodeB “eNodeB”). A cell area is a geographical area where radio coverage is provided by the base station equipment at a base station site. The base stations communicate through radio communication channels with UEs within range of the base stations.
Some cellular radio communications systems (including 3GPP LTE) are considering reduced/low complexity air interfaces to support, for example, so-called machine-type communications, also referred to as machine-to-machine or M2M communications. Demand for low/reduced-complexity air interfaces may be driven by increasing numbers of low/reduced data rate wireless data connections between/among numerous self-directed machines and/or between the self-directed machines and the network.
Third Generation Partnership Project (3GPP) Long-Term Evolution (LTE) uplinks (ULs) may be characterized by Discrete Fourier Transform Spread Orthogonal Frequency Domain Multiplexing (DFTS-OFDM) transmission, which may benefit from relatively low/reduced Peak-to-Average Power Ratio (PAPR) and thus more efficient power amplification. More particularly, a DFTS-OFDM transmitter may use both Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) operations to confine transmission to an assigned wireless terminal (user) bandwidth. Despite advances in Complementary Metal Oxide Semiconductor (CMOS) technologies, implementation of FFT and/or IFFT may be challenging, especially, when targeted for low/reduced complexity (e.g., low/reduced-power and/or low/reduced-cost) devices.
Accordingly, there may continue to exist a need for transmitter structures, for example, that are adapted to support relatively low power and/or low data rate wireless communications in radio access networks.